Drill bit adapter with depth adjustment function

Abstract

This invention provides a drill bit adapter with a depth adjustment function that allows for adjustment of the depth of the hole drilled in the workpiece, and enables easy attachment of the drill bit to a long joint without damaging or scratching the workpiece during drilling. [Solution] The main body 2, to which a drill hole depth adjustment part 6 is attached at one end, is a cylindrical body with both ends open. The bit insertion part 8 is partially inserted into the main body 2 from the other end side along the axis of the main body 2, and has a gap between it and the main body 2. A drill bit is inserted into one end of the bit insertion part 8, and the other end protrudes outward from the other end of the main body 2 and is coupled to a rotary drive. A fixing part 22 is provided on the outer circumferential surface of the bit insertion part 8 so as to be able to move back and forth along the axis. When the bit insertion part 8 is slid toward one end side of the main body 2, a drill bit can be inserted into the bit insertion part 8, and when it is slid toward the other end side of the main body 2, the drill bit can be fixed. The bearing 30 houses the bit insertion part 8 inside, its outer circumferential surface is in contact with the inside of the main body 2, and supports the bit insertion part 8 in the main body so as to be rotatable around the axis. The outer circumferential surface 30a of the bearing 30 is crimped into the main body 4, and the inner circumferential surface 30b is gap-fitted into the bit insertion part 8.

Description

Technical Field

[0001] The present invention relates to an adapter for a drill bit that is interposed between the drill bit and an electric drill or the like when the drill bit is attached to the electric drill or the like, and particularly to an adapter with a depth adjustment function.

Background Art

[0002] Patent Document 1 discloses an example of a conventional drill hole depth adjuster. This adjuster has a cylindrical portion that is inserted into the blade portion of the drill bit, and a male screw is formed on the outer peripheral surface thereof. An annular body having an internal thread that engages with this male screw is fixed to the cylindrical portion in order to fix the cylindrical portion to the blade of the drill. With this adjuster, the tip of the cylindrical portion is arranged at a desired position from the tip of the drill blade, and the cylindrical portion is fixed at that position by the annular body. In this state, when a hole is drilled in the workpiece by the drill bit, the hole cannot be drilled deeper than the depth from the tip of the drill blade to the tip of the cylindrical portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] With this adjuster, since the cylindrical portion is directly attached to the drill blade, when the drill bit is rotated, it is likely to vibrate and is likely to damage the workpiece during cutting. Further, the annular body must be screwed onto the cylindrical portion, and this operation is troublesome and likely to damage the drill bit.

[0005] An object of the present invention is to provide an adapter for a drill bit with a construction hole depth adjustment function that can perform cutting without damaging the workpiece, can attach the drill bit without damaging the drill bit, and enables easy attachment of the drill bit. [Means for solving the problem]

[0006] One embodiment of the present invention, a drill bit adapter with a drill hole depth adjustment function, has a main body. This main body is a cylindrical body with both ends open, and a drill hole depth adjustment part is attached to one end. A bit insertion part is inserted along the axis of the main body from the other end side of the main body such that a portion of it is located inside the main body. This bit insertion part is a long body with one end inside the main body, into which a drill bit is inserted. The portion of the bit insertion part that is inside the main body has a gap between it and the inner circumferential surface of the main body. The other end of the bit insertion part protrudes outward from the other end of the main body and is coupled to a rotary drive tool, such as an impact driver. A fixing part is provided on the outer circumferential surface of the bit insertion part so as to be slidable along the bit insertion part. The drill bit can be inserted into the drill bit insertion portion when the fixing portion is sliding, for example, toward one end of the main body, or when the main body is sliding toward the other end of the main body, and the drill bit can be fixed when the fixing portion is sliding toward the other end of the main body, or when the main body is sliding toward one end of the main body. A bearing housing the bit insertion portion has its outer circumferential surface in contact with the inside of the main body and supports the bit insertion portion so as to be rotatable around the axis. The outer circumferential surface of the bearing is crimped into the main body, and the inner circumferential surface of the bearing is gap-fitted into the bit insertion portion.

[0007] In this configuration of a drill bit adapter with a drill hole depth adjustment function, the fixing part has the bit insertion part fitted into a bearing, so the fixing part can move back and forth relative to the bit insertion part together with the main body. Therefore, for example, if the fixing part is slid toward one end of the main body together with the main body while the bit insertion part is fixed, the drill bit can be inserted into the bit insertion part. If the fixing part is slid toward the other end of the main body together with the main body in this state, the inserted drill bit can be fixed in place. Alternatively, if the fixing part and the main body are fixed and the bit insertion part is slid toward the other end of the main body, the drill bit can be inserted into the bit insertion part, and if the bit insertion part is slid toward one end of the main body from this state, the drill bit can be fixed in place. Thus, the drill bit can be attached to the bit insertion part by operating the main body or the bit insertion part, and there is no need to provide a separate operating member for attaching the drill bit inside the main body, thus simplifying the configuration. Furthermore, when the drill bit is attached to the drill bit insertion section, the drill bit does not come into contact with the main body or the screw hole adjustment section, preventing damage to the drill bit. Also, the drill bit is less likely to vibrate during cutting, allowing for a consistent hole depth.

[0008] Alternatively, a locking mechanism, such as a ball, that can move back and forth within the space inside the bit insertion section can be provided within the wall of the bit insertion section. When the drill bit is inserted into the bit insertion section with the fixing section slid toward one end, the shape of the fixing section can be configured such that the locking mechanism can retract from the internal space of the bit insertion section. When the fixing section is then slid toward the other end of the main body, or when the bit insertion section is slid toward one end of the main body, the shape of the fixing section can be configured such that the locking mechanism contacts the drill bit and fixes it in place. A pressing mechanism, such as a coil spring, can also be provided inside the fixing mechanism to press the fixing section against the drill bit insertion section.

[0009] When a drill bit is inserted into the bit insertion section and the bit insertion section is connected to the rotary drive section and the rotary drive section is rotated, the bit insertion section also rotates. However, since the main body maintains a coaxial positional relationship with the bit insertion section via a bearing, if the drilling hole depth adjustment section at one end of the main body comes into contact with the workpiece, these parts will spin freely, and the workpiece will not be damaged. Furthermore, because there is a gap between the drill insertion section and the main body, the drill bit inserted into the drill bit insertion section and the main body do not come into contact while the drill bit is rotating.

[0010] In the above-described adapter for a drill bit with a drill hole depth adjustment function, the fixing portion can also be made larger in diameter than the bit insertion portion, allowing the bearing to make contact. With this configuration, the fixing portion can be reliably slid together with the main body.

[0011] Furthermore, the drill hole depth adjustment section can be formed in a cylindrical shape and attached to the main body so that the amount of protrusion from one end of the main body can be changed. With this configuration, the depth of the drill bit hole can be adjusted arbitrarily. In this case, threads can be formed on the surface of the main body, and threads that screw into the threads of the main body can be formed on the inner circumferential surface of the drill hole depth adjustment section, and the depth of the screw hole can be adjusted by adjusting the screw position. [Effects of the Invention]

[0012] In the drill bit adapter with drilling hole depth adjustment function according to this invention, the drill bit can be attached to the drill bit insertion part by operating the main body, eliminating the need for a separate operating member for attaching the drill bit inside the main body and simplifying the structure. Furthermore, when the drill bit is attached to the drill bit insertion part, the drill bit does not come into contact with the main body or the screw hole adjustment part, preventing damage to the drill bit, and reducing vibration during cutting, allowing for a consistent hole depth. [Brief explanation of the drawing]

[0013] [Figure 1]These are a front view, a longitudinal cross-sectional view, and a partially enlarged view of a drill bit adapter with a drill hole depth adjustment function according to one embodiment of the present invention. [Figure 2] Figure 1 shows a front view and a longitudinal cross-sectional view of the long joint used in the adapter. [Figure 3] Figure 2 is an exploded perspective view of the long joint. [Figure 4] Figure 1 is a perspective view of the adapter. [Figure 5] Figure 1 shows a front view and a perspective view of the adapter with a drill bit attached. [Modes for carrying out the invention]

[0014] One embodiment of the present invention, a drill bit adapter with a drilling hole depth adjustment function, has a main body 2 and a long joint 4, as shown in Figures 1(a) to (c).

[0015] The main body 2 is formed in a single cylindrical shape with both ends open, and as shown in Figures (a) and (b), a construction hole depth adjustment section 6 is attached to one end. This construction hole depth adjustment section 6 will be described later.

[0016] A long joint 4 is positioned on the other end of the main body 2. The long joint 4 is an elongated body positioned along the axis of the main body 2, for example, the central axis, with one end located inside the main body 2 and the other end protruding outside the main body 2.

[0017] As shown in Figures 1(a) and 1(b), the long joint 4 has a drill bit insertion portion 8. As shown in Figures 2(a) and 2(b), this drill bit insertion portion 8 has a roughly rod-shaped connecting portion 10 that is coupled to, for example, the chuck of an impact driver, and a cylindrical insertion portion 12 on one end of the connecting portion 10. The drill bit insertion portion 8 is arranged such that the connecting portion 10 protrudes from the other end of the main body portion 2, and the insertion portion 12 is located inside the main body portion 2.

[0018] One end of the insertion portion 12 (opposite to the coupling portion 10) is formed with a reduced-diameter portion 16 having a smaller diameter than the main portion 14 of the insertion portion 12. As shown in FIG. 3, at the boundary between the reduced-diameter portion 16 and the main portion 14, two through-holes 18 penetrating the inside and outside of the reduced-diameter portion 16 are arranged at an interval of 180 degrees. In each of these through-holes 18, locking means, for example, balls 20, are arranged so as to be able to advance and retreat within the through-holes 18.

[0019] On the outer peripheral surface of the reduced-diameter portion 14, a cylindrical fixing portion 22 is arranged so as to be able to advance and retreat along the axis of the main body portion 2 with respect to the insertion portion 12. In a state where the fixing portion 22 overlaps the reduced-diameter portion 14 as shown in FIG. 2(b), the body portion 22a contacts the ball 20 and presses toward the inside of the insertion portion 12. The rear portion 22b following the body portion 22a is in contact with the outer peripheral surface of the main portion 14. In a state where the fixing portion 22 slides toward one end side of the main body portion 2 along the axis, the ball 20 can retreat to the outside of the main portion 14. A spring chamber 22c is formed around the outer peripheral surface of the main portion 14 at the front portion of the body portion 22a. A spring 24 is arranged in this spring chamber 22c and presses the fixing portion 22 toward the main portion 14 side. Reference numerals 26 and 28 denote fixtures for the spring 24.

[0020] As shown in FIG. 1(b), this long joint 4 is rotatably supported around the axis of the main body portion 2 via a bearing, for example, a ball bearing 30. Specifically, near the boundary between the outer peripheral surface of the main portion 14 of the long joint 4 and the fixing portion 22, it is inserted into the ball bearing 30 at the other end of the main body portion 2. As shown enlarged in FIG. 1(c), the outer ring 30a of the ball bearing 30 is press-fitted into the other end of the main body portion 2, and the inner ring 30b is clearance-fitted to the main portion 14. Therefore, the fixing portion 22 and the main portion 14 can advance and retreat along the central axis of the main body portion 2. Note that reference numeral 32 denotes a retaining member for the bearing 30 and is attached to the main portion 14 of the long joint 4 in contact with the ball bearing 30.

[0021] The construction hole depth adjuster 6 provided at one end of the main body 2 is formed in a short cylindrical shape as shown in Figs. 4(a) and (b), and cutouts 34 are formed at 180-degree intervals on the tip side thereof. These cutouts 34 are for preventing chips cut by a drill bit from staying in the construction hole depth adjuster 6. A male thread 36 is formed on the outer peripheral surface of the main body 2, and a female thread 38 that engages with this male thread 36 is formed on the inner peripheral surface of the construction hole depth adjuster 6. By changing the screwing position of the construction hole depth adjuster 6 onto the main body 2, the depth of the drill hole formed by the drill bit can be adjusted. As shown in Fig. 1(b), a female thread formed on the inner peripheral surface of the annular portion 40 is screwed onto the male thread 36 on the outer peripheral surface of the main body 2 in a state of contacting the rear end portion of the construction hole depth adjuster 6, preventing the construction hole depth adjuster 6 from retreating toward the other end side of the main body 2 along the axis of the main body 2. In addition, four elongated discharge ports 42 for preventing chips cut by the drill bit from staying in the construction hole depth adjuster 6 are formed in the main body 2 at 90-degree intervals. In Figs. 1(a) and (b), the male thread 36 is omitted because the drawing is intricate.

[0022] When attaching a drill bit 42 to the drill bit adapter with drill bit depth adjustment function configured in this way, as shown in Figure 5, for example, the coupling part 10 of the drill bit insertion part 8 is connected to the chuck of an impact driver, and the main body 2 is pulled to one end (left side in Figure 1(b)) as indicated by the arrow. The outer ring 30a of the ball bearing 30 is tightly fitted to the other end of the main body 2, and the inner ring 30b is gap-fitted to the main part 14 of the drill bit insertion part 8, so the fixing part 22 moves to one end of the main body 2 together with the main body 2, and the balls 20, 20 move to the outside of the drill bit insertion part 8. In this state, the drill bit 42 is inserted into the drill bit insertion part 8 via the drill bit depth adjustment part 6 and the main body 2. In this state, when the force applied to pull the main body 2 by the drill bit spring 24 is released, the restorative force of the drill bit spring 24 returns the main body 2 and the fixing part 22 to their original positions. As a result, the balls 20, 20 move to the inside of the drill bit insertion part 8 and press against the drill bit 42, thereby fixing the drill bit 42 in place. Note that the male thread 36 and female thread 38 are omitted in Figures 5(a) and (b) to avoid diagrammatic complexity.

[0023] After attaching the drill bit 42, the screw position of the drilling hole depth adjustment section 6 is adjusted, and the fixing section 40 is moved to the position corresponding to that adjustment to prevent the drilling hole depth adjustment section 6 from moving. Then, when the impact driver is rotated, the drill bit 44 also rotates along with it, drilling a hole in the workpiece, but the main body section 2 and the drilling hole depth adjustment section 6 rotate freely due to the ball bearings 30, and do not damage the workpiece. To remove the drill bit 42, the operation is reversed from the above order.

[0024] Conversely to the above example, the main body 2 can also be held in place, for example, by hand, and the drill bit 42 can be attached to the long joint 4 by sliding the drill bit insertion part 8 toward the other end of the main body 2, and the drill bit 42 can be fixed by returning the drill bit insertion part 8 toward one end of the main body 2 by the restorative force of the spring 24.

[0025] In this drill bit adapter with drill hole depth adjustment function, the drill bit 42 can be attached to the long joint 4 by sliding the main body 2 to which the screw hole adjustment part 6 is attached, eliminating the need for a separate mechanism for attaching and detaching the drill bit 42 to the long joint 4. Furthermore, since the drill hole depth adjustment part 6 is located on the main body 2 and does not come into contact with the drill bit 42, the drill bit 42 will not be damaged by the drill hole depth adjustment part 6, and the drill bit 42 is less likely to wobble while drilling, allowing for the drilling of holes to a consistent depth. [Explanation of Symbols]

[0026] 2 Main body 4 Long joint 6. Hole depth adjustment section 8. Drill bit insertion section 22 Fixed part 42 Drill Bits

Claims

1. A cylindrical body with both ends open, the main body having a construction hole depth adjustment part attached to one end, A long body having a gap between itself and the main body, with a portion inserted into the interior of the main body along the axis of the main body from the other end of the main body, a drill bit being inserted into one end inside the main body, and the other end protruding outward from the other end of the main body being coupled to a rotary drive device, A fixing portion is provided on the outer circumferential surface of the bit insertion portion so as to be slidable along the axis of the bit insertion portion, the drill bit can be inserted into the drill bit insertion portion when it is sliding relative to the other end of the main body portion, and the drill bit can be fixed when it is sliding relative to one end of the main body portion. A bearing is provided which houses the bit insertion portion inside, has its outer surface in contact with the main body, and supports the bit insertion portion so as to be rotatable around the axis, A drill bit adapter with depth adjustment function, wherein the bearing has an outer circumferential surface that is tightly fitted to the main body and an inner circumferential surface that is gap-fitted to the bit insertion portion.

2. The drill bit adapter with depth adjustment function according to claim 1, wherein the fixing portion has a larger diameter than the bit insertion portion and the bearing can make contact with it.

3. The drill bit adapter with depth adjustment function according to claim 2, wherein the drilling hole depth adjustment part is formed in a cylindrical shape and is attached to the main body so as to be able to change the amount of protrusion from one end of the main body.

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